MagTek OMTD 99875144 - Manual (Page 22)

OMTD OPOS for MagTek Devices
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LONG Claim (LONG Timeout)
Called to acquire exclusive access to the device. The Timeout parameter gives the maximum
number of milliseconds to wait for exclusive access to be satisfied. If zero, the method attempts
to claim the device, then returns the appropriate status immediately. If OPOS_FOREVER (-1),
the method waits as long as needed until exclusive access is satisfied.
LONG Release ()
Call this method to release exclusive access to the device. If the DeviceEnabled property is
TRUE and the device is an exclusive-use device, then the device is first disabled.
LONG CheckHealth (LONG Level)
Called to test the state of a device. A text description of the results of this method is placed in
the CheckHealthText property. The CheckHealth method is always synchronous.
LONG ClearInput ()
Called to clear all device input that has been buffered. Any data events or input error events that
were enqueued – usually waiting for DataEventEnabled to be set to TRUE and FreezeEvents
to be set to FALSE – are also cleared.
LONG ClearOutput ();
Called to clear all device output that has been buffered. Also, when possible, halts outputs that
are in progress. Any output error events that were enqueued – usually waiting for FreezeEvents
to be set to FALSE – are also cleared.
LONG DirectIO (LONG Command, LONG* pData, BSTR* pString)
Call to communicate directly with the Service Object.
This method provides a means for a Service Object to provide functionality to the application
that is not otherwise supported by the standard Control Object for its device class. Depending
upon the Service Object’s definition of the command, this method may be asynchronous or
synchronous.
Use of DirectIO will make an application non-portable (e.g., it will not work with service
objects developed by other companies). The application may, however, maintain portability by
performing DirectIO calls within conditional code. This code may be based upon the value of
the ServiceObjectDescription, DeviceDescription, or DeviceName property.